""""SLS is simply one more government project, liberally marinated in absurdity, that continues because it has, thus far, flown below the publicís radar. Absent public outrage or, even worse, public ridicule, many such projects have soldiered on in obscurity for long periods based entirely on the politics of parochial self-interest and mutual back-scratching. But no amount of political influence tends to be able to save these things when the general public takes note. Especially when they laugh.""""

And what does SLS do that can't be done with 2 or 3 Falcon Heavy launches? No single module for space exploration needs to mass more than 60 tons.

SLS is designed for delivering large payloads to BLEO not LEO. You need to compare FH BLEO capabilities with SLS not its LEO.

SLS can deliver 25t Orion and crew to DSG in single launch. When FH can do this in single launch then there is case for replacing SLS.

To DSG that doesnít exist and isnít paid for, and without a proper budget uplift cant afford to be paid for without cancelling some big line item (like SLS)

Gerst specifically noted that DSG production/flight is covered under NASA's current allocation (part of why the proposal is probably 2/year instead of something more aspirational), but things like DST or Lunar Landers would require uplifting the budget.

It would be useful to see a price table: - Falcon 9, Falcon Heavy- Reusable Mode with new boosters, with used once boosters, with used twice boosters- Expendable Mode with new boosters, with used boosters, with used twice boosters

Anyway that is beside the point of article. NASA has spent $10 billion on their Heavy Lift Rocket (and another $6 billion on Orion).

And what does SLS do that can't be done with 2 or 3 Falcon Heavy launches? No single module for space exploration needs to mass more than 60 tons.

The only reputed benefit over Falcon Heavy was the wider payload fairing, which might be useful for Mars entry heat shields. (Or I could see it being an advantage for large solar arrays which can't be packed so tightly). New Glenn might over come that issue.

So with hindsight, SLS should have been cancelled years ago, and the $10 billion spent on an upper stage rocket, or a space tug, or electric space tug. Orion could still be useful - and maybe a tender put out for a commercial heavy lift vehicle to carry it. Then there might be a choice of SpaceX or Boeing or New Glenn for heavy lift packages, and NASA could get completely out of the launch business and focus on space exploration.

Moving forward, can the politicians who have wasted the SLS money pay for it out their pockets?

SLS will now be completed, and have a test flight and a ceremonial flight. But then what? Every time NASA has a mission, manned or unmanned, they say it'll cost $1 billion to launch on SLS, or $180 million on Falcon Heavy. How does it work in NASA - does the top mandate the launch vehicle for every mission?

Perhaps they will be able to come up with a compromise. Falcon Heavy launches the fuel, and SLS launches the mission. But with that architecture, you don't need Block 2 in that case.

New Glenn might make it look worse for NASA. If there are two rockets able to lift >45 tons, at a fraction of the cost of SLS, who is going to be interested in using SLS?

FH launch will be the 1st nail in the coffin of SLS. As soon as BFR launches successfully then SLS will be totally overpriced and obsolete. Hopefully the money wasting SLS will be cancelled long before BFR flies. Perhaps BO should announce NA which should pave the way for SLS's cancellation.

The SLS will continue development, which would only make sense given that nearly all the flight hardware has been made for EM-1, and flight hardware is already in process for EM-2

And then be cancelled after EM-2 if it does not get cancelled before EM-2 gets off the ground. EM-1 is likely to launch but any SLS launches after that are likely highly uncertain. If SLS is cancelled before EM-2 then EM-2 hardware already built will likely to go to museums. SLS will definitely not exist once the new generation of fully reusable HLLV's enter service.

It would be a Kerbal Kludge; but an SLS using 4x Falcon 9 Block 5's as strap on, flyback boosters would have extraordinary capability. Hey, Dr Steve Pietrobon; have at it!

Each F9 is roughly an F-1 engine, so yeah that should work quite well. Haven't got the time now to do that though.

Back on topic. With SpaceX cancelling the Lunar and Mars Dragon 2 missions to concentrate on BFR, I believe that has given SLS a lifeline for now. I believe BFR will take much longer than expected, more like 10 years than five. I think a Dragon 2 going around the Moon before Orion had a good chance of killing SLS.

BO can speed up the killing of SLS by announcing NA as an alternative to SLS for NASA. No doubt NA will have more capability than SLS at a cost comparable to BFR. Absolutely no need for SLS when both BFR and NA are in service. Could get up to around 50 launches of a mix of BFR and NA for the cost of a single SLS launch. The economics just totally stack up against SLS.

It would be a Kerbal Kludge; but an SLS using 4x Falcon 9 Block 5's as strap on, flyback boosters would have extraordinary capability. Hey, Dr Steve Pietrobon; have at it!

Each F9 is roughly an F-1 engine, so yeah that should work quite well. Haven't got the time now to do that though.

Back on topic. With SpaceX cancelling the Lunar and Mars Dragon 2 missions to concentrate on BFR, I believe that has given SLS a lifeline for now. I believe BFR will take much longer than expected, more like 10 years than five. I think a Dragon 2 going around the Moon before Orion had a good chance of killing SLS.

BO can speed up the killing of SLS by announcing NA as an alternative to SLS for NASA. No doubt NA will have more capability than SLS at a cost comparable to BFR. Absolutely no need for SLS when both BFR and NA are in service. Could get up to around 50 launches of a mix of BFR and NA for the cost of a single SLS launch. The economics just totally stack up against SLS.

True, but the reasons that Musk backs off from challenging the SLS directly are equally true for Bezos.

No direct impact, but FH in many ways cleared the way for BFR, which will have big impact on SLS.

Although just goes by some of the comments in this thread I wonder if even BFR can kill SLS, here's some of the arguments I predict we'll see when BFR flies:1. BFR and SLS can compliment each other, why can't we have both? 2. BFR can't launch Orion, so SLS is still needed3. SLS can send 30t+ to TLI in one launch, BFR couldn't, so SLS is superior!4. No impact to SLS, remember BFR hasn't just come to the scene, it's x years late already...5. But we have invested so many billions into SLS, it has hardware, we can't just cancel it6. BFR hasn't demonstrated x number of flights per year, it's still powerpoint!

Now try replacing FH/BFR with Starship Enterprise, and most of the arguments still work, what does this tell you...

1. BFR and NA replace SLS because SLS is so dammed expensive.2. BO designs NA to launch Orion as a payload option so SLS not needed.3. NA may be superior to SLS for TLI.4. SLS can no way compete with BFR and NA forcing it's cancellation.5. Just cancel SLS, give it up as a bad job to stop further money bleeding and hand over funding for BFR and NA dev.6. US of BFR may start testing by the time EM-1 launches.

So all in all SLS needs to be cancelled now to stop billions more $ being wasted.

1. BFR and NA replace SLS because SLS is so dammed expensive.2. BO designs NA to launch Orion as a payload option so SLS not needed.3. NA may be superior to SLS for TLI.4. SLS can no way compete with BFR and NA forcing it's cancellation.5. Just cancel SLS, give it up as a bad job to stop further money bleeding and hand over funding for BFR and NA dev.6. US of BFR may start testing by the time EM-1 launches.

So all in all SLS needs to be cancelled now to stop billions more $ being wasted.

Unfortunately, SLS is doing precisely what it was intended to do. Spread lots of pork around to lobbyists and constituents. It's not called the Senate Launch System for nothing, and as long as the money keeps flowing, the project will continue, launch or not.

1. BFR and NA replace SLS because SLS is so dammed expensive.2. BO designs NA to launch Orion as a payload option so SLS not needed.3. NA may be superior to SLS for TLI.4. SLS can no way compete with BFR and NA forcing it's cancellation.5. Just cancel SLS, give it up as a bad job to stop further money bleeding and hand over funding for BFR and NA dev.6. US of BFR may start testing by the time EM-1 launches.

So all in all SLS needs to be cancelled now to stop billions more $ being wasted.

Unfortunately, SLS is doing precisely what it was intended to do. Spread lots of pork around to lobbyists and constituents. It's not called the Senate Launch System for nothing, and as long as the money keeps flowing, the project will continue, launch or not.

Perhaps Musk and Bezos should get together and force NASA to cancel SLS and to fund their HLV systems.

I don't think its politically feasible to cancel SLS outright (its the Senate Launch System, after all). The vested interests are just too entrenched and the pork is too widely distributed. Nor do I think NASA can be weened from SLS and shift its focus exclusively to Habs, DSG/T, and landers instead.

The best we can hope for is some type of Lunar-COTS-style arrangement (providing supplies and crew rotation to some national or international lunar-orbiting habitat) which will generate a revenue stream for SpaceX or other providers. Hopefully, that's enough, along with revenue from satellite launches, to allow SpaceX to pursue BFR development and flights to the Mars system without delay. BO is a different case and can rely on the deepest pockets on the planet assuming he has any interest in BEO travel.

Could a rocket (such as SLS) continue its existence if her direct competitors offer cheaper options?

Could such a rocket exist and fly, even if it has limited use (i.e. missions to lunar orbit) and no commercial launches?

The answer should be a theoretical yes. But could it be, in this specific case?

BFR and NA will totally price SLS out of the market. The estimated $1 billion cost per launch of SLS is absolutely insane especially in the light of the BFR announcement last IAC. Cost of BFR per launch will be cheaper than F9 with 1st stage reuse never mind SLS and NA will likely be competitive with BFR on launch cost. Expendable launchers such as SLS won't stand a chance in a few years time as the launch market moves towards reusable systems.

1. BFR and NA replace SLS because SLS is so dammed expensive.2. BO designs NA to launch Orion as a payload option so SLS not needed.3. NA may be superior to SLS for TLI.4. SLS can no way compete with BFR and NA forcing it's cancellation.5. Just cancel SLS, give it up as a bad job to stop further money bleeding and hand over funding for BFR and NA dev.6. US of BFR may start testing by the time EM-1 launches.

So all in all SLS needs to be cancelled now to stop billions more $ being wasted.

Unfortunately, SLS is doing precisely what it was intended to do. Spread lots of pork around to lobbyists and constituents. It's not called the Senate Launch System for nothing, and as long as the money keeps flowing, the project will continue, launch or not.

Perhaps Musk and Bezos should get together and force NASA to cancel SLS and to fund their HLV systems.

They couldn't do any such thing, even if they tried to do what you propose. A. NASA is not in charge of deciding how its budget is spent, Congress is; and B. that's not how federal funding works. If Congress cancels a project, that money isn't redistributed, it's just gone.

"One bit of advice: it is important to view knowledge as sort of a semantic tree -- make sure you understand the fundamental principles, ie the trunk and big branches, before you get into the leaves/details or there is nothing for them to hang on to." - Elon Musk"There are lies, damned lies, and launch schedules." - Larry J

On another thread they listed FH's cost. Very cheap in comparison to SLS. If NASA or even if SpaceX offered to use FH as a moon centric alternative, with LEO refueling or fuel depot, an L1 station using Bigelow modules. A reusable and refuelable moon lander.

1) Say use a stretched upper stage for a fuel depot with docking and filling connections. 2) Design a large reusable moon lander that can fit either inside the existing or proposed widened and stretched fairing.3) Place a Bigelow 330 module at L1 with a stretched upper stage used for fuel depot. Also place the reusable moon lander here. 4) Launch a Dragon II and refuel the upper stage and fly to L1 to dock at station. 5) Lander lands on moon, delivers cargo or people for moon base work. Has enough fuel to return to L1.

It would make sense to use metholox architecture or maybe hydrolox. All this would depend on help from NASA, ULA, BO, or Orbital/ATK. All the money spent on SLS could help these launch providers develop the architecture to fit their launchers.

The SLS is becoming the national equivalent of California's Bullet Train. Way overpriced, benefits only the connected companies and unions that are pushing it, falling behind schedule more and more and, if it ever does becomes operational, will seldom be used because of its expense.